The present invention relates to flexible tubes and relates in particular to flexible plastic tubes useful in endoscopes or in similar diagnostic medical, veterinary or industrial appliances.
The prior art is replete with such flexible tubes, representative examples of which are shown and described in U.S. Pat. Nos. 3,739,770 and 3,946,727 issued June 19, 1973, and Mar. 30, 1976, respectively, and both assigned on the face of each patent to Olympus Optical Co., Ltd., Tokyo, Japan.
The '770 patent shows a pair of helically wound metal strips 41 and 42 wound in opposite hands.
The '727 reference shows a single helical winding metal 11 covered by resin sheath 13.
Other structures comprise a string of metal or plastic rings connected together in one fashion or another so that the rings pivot or telescope partially into one another to encourage flexibility.
It is a principal object of the present invention to provide a novel plastic flexible tube structure that requires no helical winding or connecting of individual piece-parts.
It is a further object of the invention to provide a flexible tube comprising an endless series of connected vertebra-like elements.
A still further feature of the invention is the provision of a low-cost flexible tube for medical, veterinary and industrial endoscopes providing internal access for tube manipulation wires, and channels for conventional accessories such as vacuum, irrigation, forceps and the like.